Influence of a Separation Grid on the Efficiency of Particulate Matter Capture in a Device With Arc-Shaped Elements

In the chemical industry, moving fluidized bed adsorbent plants are widely used due to the high intensity of interaction between the streams. In this case, particles formed as a result of collision with each other and with the reactor wall need to be removed from the exhaust gases. Such necessity is caused by a number of reasons: reduction of efficiency of operation of subsequent installations, erosive wear of equipment mechanisms, loss of part of the catalyst, etc. The design of a separation unit is proposed. In this paper we propose a design of a separation device with arc-shaped elements for separation of dispersed particles and gas. Its three-dimensional model is presented and the principle of operation is described. It is shown that one of the problems of its application is upward parasitic flows returning the captured particles back into the flow. To solve the problem, a separation grid is proposed. The aim of the work is to investigate the influence of the separating grid design on the efficiency of solid particles catching in the device with arc-shaped elements. To establish the influence of the linear dimensions of the separation grating on the efficiency of particle capture, three cases were considered - 1. the height of the upper part of the grating h1 increased from 10 to 60 mm, the height of the lower part of the grating h2 decreased from 90 to 40 mm, the height of the grating hgr remained constant, 2. the height h1 increased from 10 to 60 mm, the height h2 remained constant, the height hgr increased from 100 to 150 mm, 3. the height h1 increased from 10 to 110 mm, the height of h2 decreased from 90 to 40 mm, the height of hgr increased from 100 to 150 mm. The study was carried out numerically in the Ansys Fluent software package. During the research, the dusty gas velocity equal to 1 m/s was set at the inlet of the device, we set atmospheric pressure at the outlet of the device. Based on the conducted studies, it was found that the use of a separation grid provides an increase in the efficiency of particle capture, since to a greater extent it blocks ascending parasitic flows. The efficiency of the separation device in capturing particles from 10 to 170 microns in size at an input velocity of 1 m/s of dusty gas is on average 88.6%. The maximum efficiency of the device with arc-shaped elements is achieved with the ratio of the upper part of the separation grate to the lower part, h1 / h2 ≥ 5/7.